動(dòng)詞不定式的時(shí)態(tài)上可分為三種，即：一般式to do，to be done；進(jìn)行式to be doing；完成式to have done，to have been done；完成進(jìn)行式to have been doing。下面談?wù)劜欢ㄊ降耐瓿审w。
一、動(dòng)詞不定式的完成體
(1)如果不定式表示的動(dòng)作是瞬間動(dòng)作時(shí)，它表示一個(gè)在現(xiàn)在或過(guò)去某時(shí)之前已經(jīng)完成的動(dòng)作；如果是延續(xù)性動(dòng)詞，它表示一個(gè)一直持續(xù)到現(xiàn)在或過(guò)去某時(shí)的動(dòng)作。
A.常見的可接不定式的完成體的有：happen，see，appear，prove，pretend，seem等。例如：
They seem to have experienced a destructive earthquake.他們似乎已經(jīng)歷了一場(chǎng)毀滅性的地震。(表示事情已經(jīng)發(fā)生)
My grandmother appeared to have lived a happy life.我奶奶似乎一直過(guò)得很幸福。(她的幸福生活一直持續(xù)到現(xiàn)在)
B.常見的可用于“主語(yǔ) + be said + to have done/been”，相當(dāng)于主動(dòng)句“People say that ...”，類似的結(jié)構(gòu)有：be reported /thought/supposed/expected/believed/considered/known等。例如：
Her husband is said to have given up smoking.據(jù)說(shuō)她丈夫已經(jīng)戒煙了。(戒煙發(fā)生在“據(jù)說(shuō)”之前)
The young girl is reported to have served the club for five years.據(jù)說(shuō)那個(gè)小姑娘已經(jīng)在這個(gè)俱樂(lè)部服役五年了。(不定式表示謂語(yǔ)動(dòng)作所處的狀態(tài))
C.常見的可以接不定式完成體的形容詞有：glad，happy，sad，disappointed，satisfied，sorry，surprised等。例如：
I’m sorry to have given you so much trouble.對(duì)不起，給您添了那么多的麻煩。
We are disappointed to have known that our team lost the game.知道了我們隊(duì)輸了這場(chǎng)比賽，我們很失望。
試比較下面不定式的一般式和完成式的區(qū)別：
I’m happy to have seen you.見到你很高興。(分手時(shí)說(shuō)的話)
I’m happy to see you.見到你很高興。 (見面時(shí)說(shuō)的話)
I’m sorry to keep you waiting for a moment.對(duì)不起，要請(qǐng)你等一會(huì)。(說(shuō)話時(shí)還未等)
I’m sorry to have kept you waiting for a long time.對(duì)不起，讓你等久了。(說(shuō)話時(shí)已經(jīng)等了很久了)
(2)be + 不定式完成時(shí)態(tài)表示本該做或想做但又未做的動(dòng)作。例如：
You were to have arrived there early that day.__那天你們應(yīng)該早點(diǎn)兒到那。(但你們晚到了。)
I was to have helped him then，but I was too busy.那時(shí)我本想幫他的忙，可我太忙了。(未幫他的忙)
(3)表示“意圖，打算”之意的動(dòng)詞如hope，wish，expect，think，suppose，want，plan，agree，mean，try等用過(guò)去時(shí)，后接不定時(shí)完成時(shí)做賓語(yǔ)時(shí)，表示想做而未做成的事情。這種意義也可用這類詞的“過(guò)去完成時(shí) + 不定式的一般式”來(lái)表達(dá)。例如：
We wished to have put out the fire in thirty minutes.(= We had wished to put out the fire in thirty minutes.) 我們本打算半小時(shí)就把火撲滅的。(結(jié)果沒(méi)有)
The engineers planned to have removed the temple before the dam was completed.(=The engineers had planned to remove the temple before the dam was completed.) 工程師們決定大壩建成之前把那座寺廟移走。
二、動(dòng)詞不定式的完成進(jìn)行體
動(dòng)詞不定式的完成進(jìn)行體表示不定式的動(dòng)作發(fā)生在謂語(yǔ)動(dòng)詞之前，并一直在進(jìn)行著。其結(jié)構(gòu)與不定式的完成體類似。如：
He is said to have been translating Lu Xun’s works into English.據(jù)說(shuō)他一直在把魯迅的作品譯成英文。(現(xiàn)仍然在譯)
He seems to have been teaching in that school for ten years.他似乎已經(jīng)在那所學(xué)校教了十年書了。(強(qiáng)調(diào)繼續(xù)教)
The kind-hearted millionaire is very happy to have been helping the disabled.那位善良的富翁一直在幫助殘疾人，并為此感到非常高興。(仍在幫助)
We supposed to have been living here till our children grew up.我們?cè)詾榭梢栽谶@一直呆下去，直到我們的孩子長(zhǎng)大。(但我們家搬了)
三、動(dòng)詞不定時(shí)完成體的被動(dòng)式
當(dāng)主語(yǔ)與不定式的動(dòng)詞有被動(dòng)關(guān)系，且不定式所表示的動(dòng)作又先于謂語(yǔ)動(dòng)詞動(dòng)作發(fā)生時(shí)，動(dòng)詞不定式就要用完成體的被動(dòng)式。例如：
The book is said to have been translated into many languages.__據(jù)說(shuō)那本書已被譯成了多種語(yǔ)言。
The oranges were thought to have all been sold out.人們認(rèn)為桔子已經(jīng)全部賣光了。
He is very sad to have lost four relatives in the earthquake.__他為這次地震中失去了四位親人而感到十分痛心。
本文來(lái)自：逍遙右腦記憶 http://www.yy-art.cn/gaozhong/328929.html
相關(guān)閱讀：日常生活中常用的口語(yǔ)句型-5